Its the wrong carb!

Hello

I have a 1983 1093cc Golf C (as well as my GTI) and it has been suffering running problems such fuel starving at high speeds (60mph+) and surging whilst under acceleration in 1st and 2nd gear. The ignition and timing has been checked and is ok and there appears to be no air leaks. A mechanic has had a go and trying to set the carb up and his opinion is that the incorrect carb is fitted. The carb is actually a Bocar Pict 34-4 which it transpires is for a VW 1600 bus 8O !!! Despite this one of my friends (who is more experienced with carbs than me) reckons that even if the carb isn’t the right we should be able to get it to run.

Before I go searching for the correct and carb etc can any one advise me if there are any other items other than the carb which could cause the running problems. Also has anyone had any experience of replacing setting up mk1 1093 carbs?

Be great to hear who else runs non-GTI mk1s

Many thanks

Hi Mark,

I dont have a non GTI Mk1 but my brother has an 1050cc A reg Polo which I have to do work on from time to time. Possibly the engines are quite similar and a Polo carb may also fit a golf? You could check out a haynes manual to get correct models of carbs or call VW. The Etka or ETOS parts software will help too. The diagrams in these will help you figure out how the correct carb connects up a fair bit.

Other things I can think of are:

Have you checked that the fuel filler neck hasn't rusted through allowing rust and dirt to enter the tank and fuel system?

Has it got an inline fuel filter under the bonnet? if so, have you changed it lately or does it look dirty?

Maybe the mechanical fuel pump has a problem?

Sorry I cant be more helpful

Ross

My second car was a Mk1 Golf C 1093cc… sigh!

As I recall mine had a Weber carburettor, but I think this was a replacement. The original was a Solex I believe. The weber was a goodie though. One screw for idle adjustment and that was that. Never missed a beat, though the fuel economy was a bit naff (probably due to me being 19 and hoofing it around everywhere though…)

I don't know much about the bus carb you have but I suspect it will be totally wrongly jetted for a 1.1 litre engine. Probably overfuelling and underfueling at various points in the rev range.

I think a visit to a scrappy could be in order!!  I'll have a look in my manual and see if I can find the carb description for you.

These engines are also REALLY sensitive to the condenser being knackered (a small capacitor screwed into the side of the dizzy). They are as cheap as chips and well worth replacing every 6 months or so. Loads of running, starting and stopping problems solved by replacing them!

Also check the coil is the right type. I had loads of problems with my mk1 C when I discovered the coil was of a Ford Escort :roll:

Cheers,

Drew.

Hi
If I remember correctly the Pict 34/4 is the right carb for the car , but it has been about 9 years since I last worked on one.
But the problem you have sounds like the carb is icing up. Check that the warm air deflector is in place on the manifold, with the hose leading up to the air box.

I still have my '82 Mk1 1272cc Golf CL, and it has the original Carb - a Solex-Pierburg 34 PIC(T)-6

Your 1093 car would have come with a Solex-Pierburg 31 PIC-6 or PIC(T)-6

The 31 or 34 refers to the mm diameter of the venturi tube (the big hole through the centre of the carb), whose size is directly related to the capacity of the engine (and how it is tuned).

This means that you need to get a different carb with a 31 mm venturi tube.

You can get a Weber aftermarket one for about ?150 (price I remember from the mid-nineties), but I recommend locating an original Solex-Pierburg one because I found that the Weber replacement one for the Mk1 is a bit primitive, and suffers badly from icing in cold weather

Hi i've run 1093 & 1272 motors, in Mk1 Golf C's & Golf Drivers. Both were miserable in the cold… Both had the original solex carbs… And both needed constant attention around the points & condenser & ignition timing areas… Also worth you checking the accelerator pump diaphram hasnt perforated (cheap fix). Prolly also worth giving the carb a once over with some carb cleaner… Annnnd if you have a paper based inline fuel filter you might find as i did several times they break down and clog up yer carb!.. :roll:

If you're getting carb icing with the Pierburg, check the following:

That it's set up correctly (mixture, idling)
That you have the pipe from above the exhaust manifold to the air-filter neck firmly attached and that there are no big holes in it.
That the vacuum hose from this neck to the orange unit in the air-filter casing is correctly fitted and airtight, and that the other vacuum hose that goes to the carb is there too

AJ's comment about the accelerator pump diaphram is important, and if you haven't done it in the last 5-10 years you should get the carb re-built (here's an excellent crowd who did it for me a few years ago - and it's still only ?90, like it was then - cheaper than a new Weber)http://www.gowerlee.dircon.co.uk/

AJ's other comment about the points and condenser aren't strictly related to the carb itself, but contact breaker points are a royal PITA (pain in the a55), and I recommend changing them to an electronic ignition conversion kit like Lumenition - with a rebuilt carb, and Lumenition, my Golf 1.3 starts anytime in any weather, using the procedures in the owners handbook:

Engine Cold:
Pump the accelerator pedal once (twice in freezing weather) and then pull out the choke to the first indent (halfway). Turn the key, without touching the choke or the accelerator pedal (starts on the first crank rotation)

Engine Warm:
Don't pull the choke out, start the engine whilst holding the accelerator pedal about halfway in. Release accelerator as engine catches.

Engine Hot:
Don't pull the choke out, start the engine whilst holding the accelerator pedal all the way in. Release accelerator as engine catches.
(this is the only time I've had trouble - stalling due to to fuel evaporation - solved by holding the accelerator in to run at about 2000RPM for about 10 secs, to get some cold fuel up from the tank)

With any carb, you'll have some icing in very cold weather, but isn't that why fuel injection was invented? :wink:

Wow - thanks for all the responses   .  I am going to spend today going through your suggestions and having a tinker - let you know how I get on.

Cheers

I run a 1093cc engine too. Your engine will have code GG and should be fitted with a Solex 31-PICT-6 carb. I would recommend getting hold of this carb from a scrappy if possible.

If the mixture and idle are OK on your carb, check there are no vacuum leaks and that the hot air duct from the exhaust manifold is intact as this can cause carb icing at high speeds, even in mild weather.

Just to update…

Did most the checks mentioned, even disconnected the autochoke and  rigged it up manually to see of there was problem here. Could not identify any of these things as the problem so assumed it must be due to the carb mismatch. Managed to get hold of a Weber replacement with manual choke (bit pricey, but no time at the moment to fart around with second hand ones and reconditioning.

Fortunately car has repaid me by now running like a dream - starting on the nail and no stalling on these cold mornings. It also flew through its MOT the other week without any issues (my first experience of this phenomenen!). Partner now using it reliably 4-5 days a week for daily 15 mile journey to and from work…

Cheers